Touch detection device and display device with touch detection function

ABSTRACT

According to an aspect, a touch detection device includes: a plurality of drive electrodes arranged in parallel with each other; and a plurality of first touch detection electrodes arranged in parallel with each other and arranged at a portion not in contact with the drive electrodes and where the first touch detection electrode forms capacitance with a drive electrode to which a drive signal is output. The drive electrodes includes a drive electrode including a plurality of subdivided electrodes an arrangement pitch of which is finer than an arrangement pitch of the drive electrodes. The drive electrode including the subdivided electrodes is provided such that switching is enabled between a first mode in which the drive signal is collectively output to the subdivided electrodes of the drive electrode and a second mode in which the drive signal is individually output to each of the subdivided electrodes of the drive electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Application No.2015-212381, filed on Oct. 28, 2015, the contents of which areincorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to a touch detection device and a displaydevice with a touch detection function.

2. Description of the Related Art

In recent years, attention has been paid to a touch detection devicethat can detect an external proximity object, what is called a touchpanel. The touch panel is, for example, mounted on or integrated with adisplay device such as a liquid crystal display device to be used as adisplay device with a touch detection function. In the display devicewith a touch detection function, various button images and the like aredisplayed on the display device, so that the touch panel can be used, inplace of a typical mechanical button, for inputting information (forexample, refer to Japanese Patent Application Laid-open Publication No.2009-244958).

A fingerprint sensor may be arranged in an electronic apparatusincluding the display device described above. The fingerprint sensordetects a characteristic pattern (shape) of a fingerprint by detectingroughness of the fingerprint of a finger of a person who touches thefingerprint sensor (for example, refer to Japanese Patent ApplicationLaid-open Publication No. 2006-24177). A detection result of thefingerprint sensor is used for personal authentication, for example.

An electronic apparatus in the related art includes a touch panel and afingerprint sensor that are separately arranged. Due to this, as aconfiguration of the fingerprint sensor, a region with which a person'sfinger is brought into contact needs to be arranged as a separate regionindependent of a detection region of a touch operation through the touchpanel.

For the foregoing reasons, there is a need for a touch detection deviceand a display device with a touch detection function in which adetection region having higher resolution used for detecting thefingerprint and the like can also be used as a detection region of thetouch operation.

SUMMARY

According to an aspect, a touch detection device that detects a touchoperation in a detection region based on variation in capacitance, thetouch detection device includes: a plurality of drive electrodesarranged in parallel with each other in the detection region; and aplurality of first touch detection electrodes arranged in parallel witheach other in the detection region, each of the first touch detectionelectrodes being arranged at a portion not in contact with the driveelectrodes and where the first touch detection electrode formscapacitance with a drive electrode to which a drive signal is output.The drive electrodes includes a drive electrode including a plurality ofsubdivided electrodes an arrangement pitch of which is finer than anarrangement pitch of the drive electrodes. The drive electrode includingthe subdivided electrodes is provided such that switching is enabledbetween a first mode in which the drive signal is collectively output tothe subdivided electrodes of the drive electrode and a second mode inwhich the drive signal is individually output to each of the subdividedelectrodes of the drive electrode.

According to another aspect, a display device with a touch detectionfunction that detects a touch operation in a detection region on adisplay surface side of the display device based on variation incapacitance, the display device with a touch detection functionincludes: a plurality of drive electrodes arranged in parallel with eachother in the detection region; and a plurality of first touch detectionelectrodes arranged in parallel with each other in the detection region,each of the first touch detection electrodes being arranged at a portionnot in contact with the drive electrodes and where the first touchdetection electrode forms capacitance with a drive electrode to which adrive signal is output. The drive electrodes includes a drive electrodeincluding a plurality of subdivided electrodes an arrangement pitch ofwhich is finer than an arrangement pitch of the drive electrodes. Thedrive electrode including the subdivided electrodes is provided suchthat switching is enabled between a first mode in which the drive signalis collectively output to the subdivided electrodes of the driveelectrode and a second mode in which the drive signal is individuallyoutput to each of the subdivided electrodes of the drive electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a configuration example of adisplay device with a touch detection function according to anembodiment;

FIG. 2 is a block diagram illustrating a configuration of a principalfunction of a first touch detection unit;

FIG. 3 is an explanatory diagram for explaining a basic principle ofmutual-capacitive touch detection and illustrates a state in which afinger is in a non-contact state or a non-proximate state;

FIG. 4 is an explanatory diagram illustrating an example of anequivalent circuit of a state in which the finger is in the non-contactstate or the non-proximate state as illustrated in FIG. 3;

FIG. 5 is an explanatory diagram for explaining the basic principle ofmutual-capacitive touch detection and illustrates a state in which thefinger is in a contact state or a proximate state;

FIG. 6 is an explanatory diagram illustrating an example of anequivalent circuit of the state in which the finger is in the contactstate or the proximate state as illustrated in FIG. 5;

FIG. 7 is a diagram illustrating an example of waveforms of a drivesignal and a touch detection signal for mutual-capacitive touchdetection;

FIG. 8 is a block diagram illustrating a configuration of a principalfunction of a second touch detection unit;

FIG. 9 is a schematic diagram illustrating a mechanism of fingerprintdetection performed by the second touch detection unit;

FIG. 10 is a plan view schematically illustrating the display devicewith a touch detection function;

FIG. 11 is a B-B cross-sectional view of a schematic structure of thedisplay device with a touch detection function according to theembodiment;

FIG. 12 is a circuit diagram of a pixel array of a display unit with atouch detection function according to the embodiment;

FIG. 13 is a perspective view of a configuration example of a driveelectrode and a touch detection electrode of the display unit with atouch detection function according to the embodiment;

FIG. 14 is an enlarged view of the area A illustrated in FIG. 10;

FIG. 15 is a schematic B-B cross-sectional view illustrating aconfiguration related to touch detection and a polarizing plate in asimplified manner in a configuration of the area A illustrated in FIG.10;

FIG. 16 is a schematic diagram illustrating an example of transition ofthe drive electrode to which the drive signal is output in a first modein the display device with a touch detection function;

FIG. 17 is a schematic diagram illustrating an example of transition ofa subdivided electrode to which the drive signal is output in a secondmode in the display device with a touch detection function;

FIG. 18 is a timing chart illustrating an operation example of thedisplay device with a touch detection function;

FIG. 19 is a timing chart illustrating another operation example of thedisplay device with a touch detection function;

FIG. 20 is a cross-sectional view illustrating a positional relationbetween a drive electrode, a subdivided electrode, a first touchdetection electrode, a second touch detection electrode, and the likeaccording to a first modification of the embodiment;

FIG. 21 is a cross-sectional view illustrating a positional relationbetween a drive electrode, a subdivided electrode, a first touchdetection electrode, a second touch detection electrode, and the likeaccording to a second modification of the embodiment;

FIG. 22 is a cross-sectional view illustrating a positional relationbetween a drive electrode, a subdivided electrode, a first touchdetection electrode, a second touch detection electrode, and the likeaccording to a third modification of the embodiment;

FIG. 23 is a plan view schematically illustrating the display devicewith a touch detection function according to a fourth modification ofthe embodiment;

FIG. 24 is a C-C cross-sectional view illustrating a positional relationbetween a drive electrode, a subdivided electrode, a first touchdetection electrode, a second touch detection electrode, and the likeaccording to the fourth modification of the embodiment;

FIG. 25 is a diagram illustrating an example of a configuration arrangedon a cover member according to the fourth modification;

FIG. 26 is a plan view illustrating an example of a positional relationbetween the first touch detection electrode and the second touchdetection electrode according to the fourth modification;

FIG. 27 is a diagram illustrating another example of arrangement of thesecond touch detection unit according to the fourth modification;

FIG. 28 is a block diagram illustrating a configuration example of thedisplay device with a touch detection function according to the fourthmodification;

FIG. 29 is a plan view illustrating a positional relation between adrive electrode, a subdivided electrode, and a second touch detectionelectrode according to a fifth modification;

FIG. 30 is a plan view illustrating a positional relation between adrive electrode, a subdivided electrode, and a second touch detectionelectrode according to a sixth modification; and

FIG. 31 is an explanatory diagram for explaining an example of anoperation of code-division multiplexed driving.

DETAILED DESCRIPTION

The following describes an embodiment in detail with reference to thedrawings. The present invention is not limited to the embodimentdescribed below. Components described below include a component that iseasily conceivable by those skilled in the art and substantially thesame component. The components described below can be appropriatelycombined. The disclosure is merely an example, and the present inventionnaturally encompasses an appropriate modification maintaining the gistof the invention that is easily conceivable by those skilled in the art.To further clarify the description, a width, a thickness, a shape, andthe like of each component may be schematically illustrated in thedrawings as compared with an actual aspect. However, this is merely anexample and interpretation of the invention is not limited thereto. Thesame element as that described in the drawing that has already beendiscussed is denoted by the same reference numeral through thedescription and the drawings, and detailed description thereof will notbe repeated in some cases.

In this disclosure, when an element is described as being “on” anotherelement, the element can be directly on the other element, or there canbe one or more elements between the element and the other element.

Embodiment

FIG. 1 is a block diagram illustrating a configuration example of adisplay device 1 with a touch detection function according to anembodiment. As illustrated in FIG. 1, the display device 1 with a touchdetection function includes a display unit 10 with a touch detectionfunction, a control unit 11, a gate driver 12, a source driver 13, adrive electrode driver 14, a first touch detection unit 40, and a secondtouch detection unit 60. In the display device 1 with a touch detectionfunction, a touch detection function is incorporated in the display unit10 with a touch detection function. The display unit 10 with a touchdetection function is a device integrating a display panel 20 includinga liquid crystal display element as a display element with a touch panel30 serving as a touch detection device for detecting a touch input(touch operation). The display unit 10 with a touch detection functionmay be what is called an on-cell device in which the touch panel 30 ismounted on the display panel 20. The display panel 20 may be, forexample, an organic electroluminescent (EL) display panel. In the touchdetection, contact on or proximity to the touch panel 30 performed by anexternal conductor can be detected as a touch operation.

As described later, the display panel 20 sequentially scans for eachhorizontal line in accordance with a scanning signal Vscan supplied fromthe gate driver 12, thereby performing display. The control unit 11 is acircuit that supplies a control signal to each of the gate driver 12,the source driver 13, the drive electrode driver 14, and the first touchdetection unit 40 based on a video signal Vdisp supplied from theoutside, thereby controlling these components to operate insynchronization with each other.

The gate driver 12 has a function of sequentially selecting onehorizontal line to be a display driving target of the display unit 10with a touch detection function based on the control signal suppliedfrom the control unit 11.

The source driver 13 is a circuit that supplies a pixel signal Vpix toeach sub-pixel SPix (described later) in the display unit 10 with atouch detection function based on the control signal supplied from thecontrol unit 11.

The drive electrode driver 14 is a circuit that supplies a drive signalVcom to a drive electrode COML (described later) in the display unit 10with a touch detection function based on the control signal suppliedfrom the control unit 11.

The touch panel 30 operates based on a basic principle of capacitivetouch detection, and performs a touch detection operation using amutual-capacitive system to detect contact or proximity of an externalconductor in a detection region including a display region 101 a (referto FIG. 10 and other figures). The touch panel 30 may perform the touchdetection operation using a self-capacitive system.

FIG. 2 is a block diagram illustrating a configuration of a principalfunction of the first touch detection unit 40. The first touch detectionunit 40 is a circuit that detects whether there is a touch operation onor to the touch panel 30 based on the control signal such as a clocksignal supplied from the control unit 11 and based on a first touchdetection signal Vdet1 supplied from the touch panel 30. The first touchdetection unit 40 obtains coordinates at which the touch input isperformed when there is a touch operation. The first touch detectionunit 40 includes a touch-detection-signal amplification unit 42, an A/Dconversion unit 43, a signal processing unit 44, and a coordinateextracting unit 45. A detection timing control unit 46 controls the A/Dconversion unit 43, the signal processing unit 44, and the coordinateextracting unit 45 based on the control signal supplied from the controlunit 11 such that they operate in synchronization with each other.

As described above, the touch panel 30 operates based on the basicprinciple of capacitive touch detection. With reference to FIGS. 3 to 7,the following describes the basic principle of mutual-capacitive touchdetection performed by the display device 1 with a touch detectionfunction according to the present embodiment. FIG. 3 is an explanatorydiagram for explaining the basic principle of mutual-capacitive touchdetection and illustrates a state in which a finger is in a non-contactstate or a non-proximate state. FIG. 4 is an explanatory diagramillustrating an example of an equivalent circuit of the state in whichthe finger is in the non-contact state or the non-proximate state asillustrated in FIG. 3. FIG. 5 is an explanatory diagram for explainingthe basic principle of mutual-capacitive touch detection and illustratesa state in which the finger is in a contact state or a proximate state.FIG. 6 is an explanatory diagram illustrating an example of anequivalent circuit of the state in which the finger is in the contactstate or the proximate state as illustrated in FIG. 5. FIG. 7 is adiagram illustrating an example of waveforms of the drive signal Vcomand the first touch detection signal Vdet1. The following describes acase in which a finger is in contact with or proximate to the touchpanel. Alternatively, for example, an object including a conductor suchas a stylus pen may be used instead of the finger. The drive signal Vcomrepresents a signal that is output to the drive electrode COML, and doesnot represent a signal corresponding to a specific voltage.

For example, as illustrated in FIG. 3, a capacitive element C1 includesa pair of electrodes arranged facing each other with a dielectric Dinterposed therebetween, that is, a drive electrode E1 and a touchdetection electrode E2. As illustrated in FIG. 4, one end of thecapacitive element C1 is coupled to an alternate current (AC) signalsource (driving signal source) S, and the other end thereof is coupledto a voltage detector DET. The voltage detector DET is, for example, anintegrating circuit included in the touch-detection-signal amplificationunit 42 illustrated in FIG. 1.

When an AC rectangular wave Sg having a predetermined frequency (forexample, about several kHz to several hundreds kHz) is applied to thedrive electrode E1 (one end of the capacitive element C1) from the ACsignal source S, an output waveform (first touch detection signal Vdet1)as illustrated in FIG. 7 appears via the voltage detector DET coupled tothe touch detection electrode E2 (the other end of the capacitiveelement C1). The AC rectangular wave Sg corresponds to the drive signalVcom input from the drive electrode driver 14, for example.

In a state in which the finger is not in contact with or proximate tothe touch panel (non-contact state), as illustrated in FIGS. 3 and 4, acurrent I₀ corresponding to a capacitance value of the capacitiveelement C1 flows with charge and discharge of the capacitive element C1.The voltage detector DET illustrated in FIG. 4 converts variation in thecurrent I₀ corresponding to the AC rectangular wave Sg into variation involtage (a waveform V₀ of a solid line (refer to FIG. 7)).

In a state in which the finger is in contact with or proximate to thetouch panel (contact state), as illustrated in FIG. 5, capacitance C2formed by the finger is in contact with or proximate to the touchdetection electrode E2, so that capacitance corresponding to a fringebetween the drive electrode E1 and the touch detection electrode E2 isshielded. Due to this, as illustrated in FIG. 6, the capacitive elementC1 functions as a capacitive element C1′ having a capacitance valuesmaller than the capacitance value in the non-contact state. Withreference to the equivalent circuit illustrated in FIG. 6, a current I₁flows through the capacitive element C1. As illustrated in FIG. 7, thevoltage detector DET converts variation in the current I₁ correspondingto the AC rectangular wave Sg into variation in voltage (a waveform V₁of a dotted line). In this case, amplitude of the waveform V₁ is smallerthan that of the waveform V₀ described above. Accordingly, an absolutevalue |ΔV| of a voltage difference between the waveform V₀ and thewaveform V₁ varies depending on influence of a conductor such as afinger that is brought into contact with or proximate to the touch panelfrom the outside. To accurately detect the absolute value |ΔV| of thevoltage difference between the waveform V₀ and the waveform V₁, it ismore preferable to provide, to an operation of the voltage detector DET,a period Reset for resetting charge and discharge of a capacitor inaccordance with a frequency of the AC rectangular wave Sg throughswitching in the circuit.

The touch panel 30 illustrated in FIG. 1 sequentially scans eachdetection block in accordance with the drive signal Vcom supplied fromthe drive electrode driver 14, thereby performing mutual-capacitivetouch detection.

The touch panel 30 outputs the first touch detection signal Vdet1 ofeach detection block via the voltage detector DET illustrated in FIG. 4or FIG. 6 from a plurality of first touch detection electrodes TDLdescribed later. The first touch detection signal Vdet1 is supplied tothe touch-detection-signal amplification unit 42 of the first touchdetection unit 40.

The touch-detection-signal amplification unit 42 amplifies the firsttouch detection signal Vdet1 supplied from the touch panel 30. Thetouch-detection-signal amplification unit 42 may include an analog lowpass filter (LPF) that removes a high frequency component (noisecomponent) included in the first touch detection signal Vdet1 andoutputs the remaining.

The A/D conversion unit 43 samples each analog signal that is outputfrom the touch-detection-signal amplification unit 42 at a timingsynchronized with the drive signal Vcom, and converts the analog signalinto a digital signal.

The signal processing unit 44 includes a digital filter that reduces afrequency component (noise component) other than a frequency at whichthe drive signal Vcom is sampled included in the output signal of theA/D conversion unit 43. The signal processing unit 44 is a logic circuitthat detects whether there is a touch operation on or to the touch panel30 based on the output signal of the A/D conversion unit 43. The signalprocessing unit 44 performs processing of extracting only a differenceof the detection signal caused by the finger. The signal of thedifference caused by the finger corresponds to the absolute value |ΔV|of the difference between the waveform V₀ and the waveform V₁ describedabove. The signal processing unit 44 may perform an arithmetic operationfor averaging the absolute value |ΔV| for each detection block to obtainan average value of the absolute value |ΔV|. Due to this, the signalprocessing unit 44 can suppress influence of the noise. The signalprocessing unit 44 compares the detected signal of the difference causedby the finger with a predetermined threshold voltage. If the signal ofthe difference is smaller than the threshold voltage, the signalprocessing unit 44 determines that an external proximity object is inthe non-contact state. If the signal of the difference is equal to orlarger than the threshold voltage, the signal processing unit 44determines that the external proximity object is in the contact state.In this way, the first touch detection unit 40 can perform touchdetection. In this way, the first touch detection unit 40 detects atouch operation based on variation in the capacitance in the first touchdetection electrode TDL.

The coordinate extracting unit 45 is a logic circuit that obtains, whena touch operation is detected by the signal processing unit 44, touchpanel coordinates at which the touch operation is detected. Thecoordinate extracting unit 45 outputs the touch panel coordinates as adetection signal output Vout1. As described above, the display device 1with a touch detection function according to the present embodiment candetect the touch panel coordinates of the position where a conductorsuch as a finger is in contact with or proximate to a touch panel, basedon the basic principle of mutual-capacitive touch detection.

FIG. 8 is a block diagram illustrating a configuration of a principalfunction of a second touch detection unit 60. The second touch detectionunit 60 is a circuit that detects whether there is a touch operation ata finer pitch than the first touch detection unit 40 based on thecontrol signal such as a clock signal supplied from the control unit 11and a second touch detection signal Vdet2 supplied from the touch panel30. The second touch detection unit 60 includes, for example, atouch-detection-signal amplification unit 62, an A/D conversion unit 63,a signal processing unit 64, a coordinate extracting unit 65, adetection timing control unit 66, and a synthesizing unit 67. Functionsof the touch-detection-signal amplification unit 62, the A/D conversionunit 63, the signal processing unit 64, the coordinate extracting unit65, and the detection timing control unit 66 are similar to thefunctions of the touch-detection-signal amplification unit 42, the A/Dconversion unit 43, the signal processing unit 44, the coordinateextracting unit 45, and the detection timing control unit 46. The secondtouch detection unit 60 is coupled to a second touch detection electrodeSTDL (refer to FIG. 14 and other figures) in the same manner as thefirst touch detection unit 40 being coupled to the first touch detectionelectrode TDL. The second touch detection signal Vdet2 from the secondtouch detection electrode STDL is supplied to the touch-detection-signalamplification unit 62 of the second touch detection unit 60.

FIG. 9 is a schematic diagram illustrating a mechanism of fingerprintdetection performed by the second touch detection unit 60. Thesynthesizing unit 67 combines second touch detection signals Vdet2 froma plurality of second touch detection electrodes STDL to generatetwo-dimensional information indicating a shape of the external proximityobject performing a touch operation on the second touch detectionelectrodes STDL. Specifically, the synthesizing unit 67 generates atwo-dimensional image representing, as a shade of color (for example, agray scale), a difference in detected intensity corresponding to adifference in a degree of contact with respect to a cover member 5(refer to FIG. 10) due to roughness of the external proximity object(for example, a finger of a person). An output Vout2 of the second touchdetection unit 60 including the synthesizing unit 67 is, for example, anoutput of the two-dimensional information described above.

FIG. 9 exemplifies two-gradation detection indicating only whether thereis a touch operation for clarification, but actually, a touch detectionresult in each block can be multi-gradation. In FIG. 9, the detectedexternal proximity object is an object having a double-circle-shapedprojection. If the external proximity object is a finger of a personhaving a fingerprint, the fingerprint pattern can be obtained as thetwo-dimensional information. The function of the synthesizing unit 67may be included in a configuration other than the second touch detectionunit 60. For example, an output of the coordinate extracting unit 65 maybe the output Vout2 of the second touch detection unit 60, and anexternal configuration may generate the two-dimensional informationbased on the output Vout2. A configuration related to generation of thetwo-dimensional information may be implemented as hardware such as acircuit, or what is called software processing.

Next, the following describes a configuration example of the displaydevice 1 with a touch detection function in detail. FIG. 10 is a planview schematically illustrating the display device 1 with a touchdetection function. FIG. 11 is a B-B cross-sectional view of a schematicstructure of the display device 1 with a touch detection function. FIG.12 is a circuit diagram of a pixel array of a display unit with a touchdetection function according to the embodiment. FIG. 10 does notillustrate a subdivided electrode SCOML and the second touch detectionelectrode STDL (described later). In the following description, thedrive electrode not including the subdivided electrode SCOML is referredto as a drive electrode COML1, the drive electrode including thesubdivided electrode SCOML is referred to as a drive electrode COML2,and the drive electrode COML1 and the drive electrode COML2 arecollectively called the drive electrode COML in some cases.

In the embodiment, a detection block, which will be described later, isa bundle of drive electrodes COML (or a bundle of subdivided electrodesSCOML) to which the drive signal Vcom is collectively output in thetouch detection. A drive electrode block, which will be described later,includes one or more drive electrodes COML. The number of driveelectrodes COML included in one drive electrode block can bepredetermined. A subdivided electrode block, which will be describedlater, includes one or more subdivided electrodes SCOML. The number ofsubdivided electrodes SCOML included in one subdivided electrode blockcan be predetermined. It is only required that the number of subdividedelectrodes SCOML included in one subdivided electrode block is less thanthe number of subdivided electrodes SCOML included in one driveelectrode COML2. The display device 1 with a touch detection function iscapable to operating in a first mode and a second mode. In theembodiment, the detection block in the first mode corresponds to thedrive electrode block, and the detection block in the second modecorresponds to the subdivided electrode block. An arrangement pitch ofthe detection blocks (detection pitch) in the second mode is finer thanan arrangement pitch of the detection blocks (detection pitch) in thefirst mode. In the embodiment, one subdivided electrode SCOMLcorresponds to one subdivided electrode block, and also corresponds toone detection block in the second mode, for example. The first mode andthe second mode will be described later in detail.

As illustrated in FIG. 10, the display device 1 with a touch detectionfunction includes a pixel substrate 2 and a counter substrate 3. Thepixel substrate 2 and the counter substrate 3 overlap each other. Theconfiguration of the display device 1 with a touch detection functionfurther includes a display control IC (not illustrated in FIG. 10). Thedisplay device 1 with a touch detection function includes, for example,a display region 101 a for displaying an image, and a picture frameregion 101 b outside the display region 101 a. For example, the displayregion 101 a has a rectangular shape having a long side and a shortside, but the shape of the display region can be appropriately changed.The picture frame region 101 b has a frame shape surrounding part of orthe entire edge of the display region 101 a.

A plurality of drive electrodes COML and a plurality of first touchdetection electrodes TDL are arranged in the display region 101 a. Thedrive electrodes COML extend in a predetermined direction of the displayregion 101 a and are arranged in parallel with each other in a directionorthogonal to the predetermined direction. Specifically, for example,the drive electrodes COML extend in a direction along a first side ofthe rectangular display region 101 a and are arranged in parallel witheach other in a direction along a second side thereof orthogonal to thefirst side. The first touch detection electrodes TDL extend, forexample, in a direction orthogonal to the predetermined direction inwhich the drive electrodes COML extend and are arranged in parallel witheach other in the predetermined direction.

The pixel substrate 2 includes a TFT substrate 21 serving as a circuitboard, a plurality of pixel electrodes 22 arranged in a matrix on theupper side of the TFT substrate 21, the drive electrodes COML arrangedbetween the TFT substrate 21 and the pixel electrode 22, and aninsulating layer 24 that insulates the pixel electrode 22 from the driveelectrodes COML. A polarizing plate 35B may be arranged on the lowerside of the TFT substrate 21 via a bonding layer.

The counter substrate 3 includes a glass substrate 31 and a color filter32 formed on one surface of the glass substrate 31. The first touchdetection electrode TDL serving as a detection electrode of the touchpanel 30 is arranged on the other surface of the glass substrate 31. Apolarizing plate 35A is arranged on the upper side of the first touchdetection electrode TDL.

The TFT substrate 21 and the glass substrate 31 are arranged facing eachother with a predetermined gap therebetween via a spacer (notillustrated). A liquid crystal layer 6 is arranged in a space betweenthe TFT substrate 21 and the glass substrate 31. The liquid crystallayer 6 modulates light passing therethrough depending on a state of anelectric field. For example, the liquid crystal layer 6 includes liquidcrystals of lateral electric-field mode such as in-plane switching (IPS)including fringe field switching (FFS). An orientation film may bearranged between the liquid crystal layer 6 and the pixel substrate 2,and between the liquid crystal layer 6 and the counter substrate 3illustrated in FIG. 11.

The TFT substrate 21 is provided with a thin film transistor element(hereinafter, referred to as a TFT element) Tr of each sub-pixel SPixillustrated in FIG. 12, and wiring such as a pixel signal line SGL thatsupplies the pixel signal Vpix to each pixel electrode 22 and a scanningsignal line GCL that supplies the drive signal Vcom for driving each TFTelement Tr. The pixel signal line SGL and the scanning signal line GCLextend along a plane parallel with the surface of the TFT substrate 21.

The display panel 20 illustrated in FIG. 12 includes a plurality ofsub-pixels SPix arranged in a matrix. Each sub-pixel SPix includes theTFT element Tr and a liquid crystal element LC. The TFT element Tr isconstituted of a thin film transistor. In this example, the TFT elementTr is constituted of an n-channel metal oxide semiconductor (MOS) TFT. Asource of the TFT element Tr is coupled to the pixel signal line SGL, agate thereof is coupled to the scanning signal line GCL, and the drainthereof is coupled to one end of the liquid crystal element LC. One endof the liquid crystal element LC is coupled to the drain of the TFTelement Tr, and the other end thereof is coupled to the drive electrodeCOML.

The sub-pixel SPix is coupled to the other sub-pixels SPix belonging tothe same row in the display panel 20 via the scanning signal line GCL.The scanning signal line GCL is coupled to the gate driver 12 (refer toFIG. 1), and receives the scanning signal Vscan supplied from the gatedriver 12. The sub-pixel SPix is coupled to the other sub-pixels SPixbelonging to the same column in the display panel 20 via the pixelsignal line SGL. The pixel signal line SGL is coupled to the sourcedriver 13 (refer to FIG. 1), and receives the pixel signal Vpix suppliedfrom the source driver 13. The sub-pixel SPix is further coupled to theother sub-pixels SPix belonging to the same column via the driveelectrode COML. The drive electrode COML is coupled to the driveelectrode driver 14 (refer to FIG. 1), and receives the drive signalVcom supplied from the drive electrode driver 14. That is, in thisexample, a plurality of sub-pixels SPix belonging to the same columnshare one drive electrode COML. The drive electrode COML according tothe present embodiment extends in parallel with an extending directionof the pixel signal line SGL, and extends in a direction intersectingwith an extending direction of the scanning signal line GCL. Theextending direction of the drive electrode COML is not limited thereto.For example, the drive electrode COML may extend in a direction parallelwith the scanning signal line GCL.

The gate driver 12 illustrated in FIG. 1 drives the scanning signallines GCL to sequentially scan each of the scanning signal lines GCL.The gate driver 12 applies the scanning signal Vscan (refer to FIG. 1)to a gate of the TFT element Tr of the sub-pixel SPix via the scanningsignal line GCL to sequentially select one line (one horizontal line) ofthe sub-pixels SPix as the display driving target. In the display device1 with a touch detection function, the source driver 13 supplies thepixel signals Vpix to the sub-pixels SPix belonging to the selected onehorizontal line via the pixel signal lines SGL illustrated in FIG. 12.The sub-pixels SPix perform display for each horizontal line based onthe pixel signals Vpix supplied to the sub-pixels SPix. During thisdisplay operation, the drive electrode driver 14 applies the drivesignal Vcom to the drive electrode COML. A common potential is suppliedto the pixel electrode 22 by the drive signal Vcom in the displayoperation.

In the color filter 32 illustrated in FIG. 11, for example, colorregions of the color filter colored in three colors of red (R), green(G), and blue (B) may be periodically arranged. Color regions of threecolors R, G, and B correspond to the sub-pixels SPix illustrated in FIG.12, and a pixel Pix is constituted of a set of sub-pixels SPixcorresponding to the color regions of three colors. As illustrated inFIG. 11, the color filter 32 faces the liquid crystal layer 6 in adirection perpendicular to the TFT substrate 21. Another combination ofcolors may be employed for the color filter 32 so long as the colors aredifferent from each other. The combination of colors for the colorfilter 32 is not limited to three colors. Alternatively, four or morecolors may be combined.

The drive electrode COML functions as a common electrode that gives acommon potential to the pixel electrodes 22 of the display panel 20, andalso functions as an electrode to which the drive signal is output inperforming mutual-capacitive touch detection of the touch panel 30. Thedrive electrode COML may also function as a detection electrode forperforming self-capacitive touch detection of the touch panel 30. FIG.13 is a perspective view of a configuration example of the driveelectrode COML and the touch detection electrode TDL of the display unit10 with a touch detection function according to the embodiment. Thetouch panel 30 includes the drive electrode COML arranged in the pixelsubstrate 2 and the first touch detection electrode TDL arranged in thecounter substrate 3.

The drive electrodes COML have a plurality of striped electrode patternsextending in a horizontal direction of FIG. 13. The first touchdetection electrodes TDL have a plurality of electrode patternsextending in a direction intersecting with the extending direction ofthe electrode patterns of the drive electrodes COML. The first touchdetection electrodes TDL face the drive electrodes COML in a directionperpendicular to the surface of the TFT substrate 21 (refer to FIG. 11).Each electrode pattern of the first touch detection electrode TDL iscoupled to an input terminal of the touch-detection-signal amplificationunit 42 in the first touch detection unit 40 (refer to FIG. 1).Capacitance is formed at each intersecting portion between eachelectrode pattern of the drive electrode COML and each electrode patternof the first touch detection electrode TDL.

A translucent conductive material such as indium tin oxide (ITO) is usedfor the first touch detection electrode TDL, the drive electrode COML,and the second touch detection electrode STDL, for example. The shape ofthe electrodes used for touch detection such as the first touchdetection electrode TDL and the drive electrode COML is not limited to aplurality of stripes. For example, the first touch detection electrodeTDL and the drive electrode COML may have a comb-teeth shape.Alternatively, it is sufficient that the first touch detection electrodeTDL and the drive electrode COML have a pattern divided into a pluralityof parts, and the shape of slits that separate the drive electrodes COMLmay be a straight line or a curved line. The same applies to the shapeof the second touch detection electrode and the subdivided electrodeSCOML described later.

When the touch panel 30 performs a mutual-capacitive touch detectionoperation, the drive electrode driver 14 drives the drive electrodesCOML to sequentially scan them in a time division manner as a driveelectrode block, so that one detection block of the drive electrode COMLis sequentially selected. When the first touch detection signal Vdet1 isoutput from the first touch detection electrode TDL, touch detection forone detection block is performed. That is, the drive electrode blockcorresponds to the drive electrode E1 in the basic principle ofmutual-capacitive touch detection described above, the first touchdetection electrode TDL corresponds to the touch detection electrode E2,and the touch panel 30 detects a touch input in accordance with thebasic principle. As illustrated in FIG. 13, in the touch panel 30, thefirst touch detection electrode TDL and the drive electrode COMLintersecting with each other constitute a capacitive touch sensor in amatrix. Thus, by scanning across the entire touch detection surface ofthe touch panel 30, a position where an external conductor is broughtinto contact with or proximate to the touch panel 30 can be detected.

The touch detection surface of the touch panel 30 also functions as adisplay surface through which a display output is performed by thedisplay panel 20. In this embodiment, the translucent cover member has afirst surface facing the counter substrate 3 and a second surfaceopposite to the first surface. The touch detection surface is the secondsurface of the cover member 5. Thus, a display region in which a displayoutput is performed by the display panel 20 overlaps with a detectionregion in which touch detection is performed by the touch panel 30. Adegree of overlapping between the display region and the detectionregion can be predetermined. For example, the detection regionpreferably covers the entire display region.

As described above, the touch panel 30 includes a plurality of driveelectrodes COML arranged in parallel with each other in the detectionregion and a plurality of first touch detection electrodes TDL arrangedin parallel with each other in the detection region, and each of thefirst touch detection electrodes TDL being arranged at a portion not incontact with the drive electrode COML and where the first touchdetection electrode TDL forms capacitance with the drive electrode COMLto which the drive signal Vcom is output. The touch panel 30 functionsas a touch detection device that detects a touch operation in thedetection region based on variation in capacitance.

A device driver integrated circuit (DDIC) 80 is on the pixel substrate2. For example, a function related to the control unit 11 and the sourcedriver 13 is implemented in the DDIC 80. Wiring through which anexternal signal (for example, the video signal Vdisp and afingerprint-detection implementation signal Vtouch) is transmitted iscoupled to the DDIC 80. Specifically, such wiring is provided as aflexible printed circuits (FPC) 70, for example.

In the embodiment, as illustrated in FIG. 10, for example, the firsttouch detection unit 40 and the second touch detection unit 60 arearranged on the FPC 70 using what is called a chip on flexible (COF)method. However, this is merely an example of a specific arrangement ofthe first touch detection unit 40 and the second touch detection unit60, and the arrangement is not limited thereto. The arrangement of thefirst touch detection unit 40 and the second touch detection unit 60 canbe appropriately modified.

In the embodiment, wiring that couples the first touch detection unit 40to the first touch detection electrode TDL is arranged as an FPC 71. Inthe embodiment, wiring that couples the second touch detection unit 60to the second touch detection electrode STDL is arranged as an FPC 72.The FPCs 71 and 72 are merely an example of a specific configuration ofthe wiring. The wiring is not limited thereto, and can be appropriatelymodified.

Next, the following describes a configuration related to fingerprintdetection. FIG. 14 is an enlarged view of the area A illustrated in FIG.10. FIG. 15 is a schematic B-B cross-sectional view illustrating aconfiguration related to touch detection and a polarizing plate in asimplified manner in a configuration of the area A illustrated in FIG.10. Part or all (drive electrode COML2) of the drive electrodes COMLinclude a plurality of subdivided electrodes SCOML that are subdividedat a finer pitch than an arrangement pitch of the drive electrodes COML.Specifically, as illustrated in FIG. 14, for example, one driveelectrode COML2 among the drive electrodes COML arranged in parallelwith each other is subdivided into some subdivided electrodes SCOML at afiner pitch than the arrangement pitch of the drive electrodes COML.More specifically, for example, when the arrangement pitch of the driveelectrodes COML is 3 mm to 5 mm, the arrangement pitch of the subdividedelectrodes SCOML is 50 μm to 300 μm. An arrangement direction of thesubdivided electrodes SCOML is the same as an arrangement direction ofthe drive electrodes COML.

A width of the region in which the subdivided electrodes SCOML of onedrive electrode COML2 are arranged in parallel with each other issubstantially the same as that of the drive electrode COML1 notincluding the subdivided electrode SCOML. In other words, by bundlingall the subdivided electrodes SCOML, the drive electrode COML2 includingthe subdivided electrodes SCOML can obtain substantially the sameelectrode width as that of the drive electrode COML1 not including thesubdivided electrode SCOML.

In FIG. 14, one drive electrode COML2 including the subdividedelectrodes SCOML is the lowermost drive electrode COML in FIG. 10, andis the drive electrode COML positioned at a lower part of the displayregion of an electronic apparatus including the display device 1 with atouch detection function, for example. However, such a specificconfiguration is merely an arrangement example of the drive electrodeCOML2 including the subdivided electrode SCOML, and can be appropriatelymodified. For example, one or more of the drive electrodes COML1 thatare not subdivided in FIG. 14 may be subdivided into some pieces toinclude the subdivided electrodes SCOML, or all the drive electrodesCOML may be the drive electrodes COML2 including the subdividedelectrodes SCOML.

The display device 1 with a touch detection function includes the secondtouch detection electrode STDL. Specifically, as illustrated in FIG. 14,for example, the second touch detection electrodes STDL are arranged inparallel with each other between the first touch detection electrodesTDL that are arranged in parallel with each other. The second touchdetection electrodes STDL are subdivided at a finer pitch than thearrangement pitch of the first touch detection electrodes TDL. Morespecifically, for example, when the arrangement pitch of the first touchdetection electrodes TDL is 3 mm to 5 mm, the arrangement pitch of thesecond touch detection electrodes STDL is 50 μm to 300 μm. Thearrangement direction of the second touch detection electrodes STDL isthe same as the arrangement direction of the first touch detectionelectrodes TDL.

In FIG. 14 and other figures, to clearly illustrate that one driveelectrode COML2 having the width corresponding to one drive electrodeCOML1 has a plurality of subdivided electrodes SCOML, the width of thesubdivided electrode SCOML is substantially equal to spacing (a width)between the subdivided electrodes SCOML. However, this is merely aschematic, and does not represent an actual width. It is only requiredthat the subdivided electrodes SCOML are separated or insulated fromeach other such that each of the subdivided electrodes SCOML can receiveindividually the drive signal Vcom. A relation between the width of eachsecond touch detection electrode STDL and the spacing between the secondtouch detection electrodes STDL is the same as the relation between thewidth of each subdivided electrode SCOML and the spacing between thesubdivided electrodes SCOML.

The second touch detection electrode STDL is arranged in a partialregion of the detection region. Specifically, as illustrated in FIG. 14,for example, the second touch detection electrode STDL is arranged in aregion between some (for example, four) of the first touch detectionelectrodes TDL present around a middle position in the detection regionin the arrangement direction of the first touch detection electrode TDL.More specifically, the second touch detection electrode STDL is arrangedin a region between two first touch detection electrodes TDL included inthe some of the first touch detection electrodes TDL and in which thefirst touch detection electrode TDL is not present.

The second touch detection electrode STDL is arranged at a portion notin contact with the subdivided electrode SCOML and where the secondtouch detection electrode STDL forms capacitance with the subdividedelectrode SCOML to which the drive signal Vcom is output. Specifically,as illustrated in FIG. 15, for example, the second touch detectionelectrode STDL is arranged on the cover member 5 that is arranged facingthe pixel substrate 2 including the drive electrode COML with the liquidcrystal layer 6 and the counter substrate 3 interposed therebetween.More specifically, the second touch detection electrode STDL is arrangedon the first surface of the cover member 5 facing the counter substrate3. The drive electrodes COML (drive electrodes COML1 and COML2) and thefirst touch detection electrodes TDL are arranged on a side of thesecond surface of the cover member 5 with which a touch operation isperformed. The drive electrodes COML and the first touch detectionelectrodes TDL are included in the respective substrates (the pixelsubstrate 2 and the counter substrate 3) to form a multilayer structure.The second touch detection electrode STDL is arranged closer to thecover member 5 than the first touch detection electrode TDL is.

As illustrated in FIG. 14, the second touch detection electrode STDL islocated at a portion overlapping the subdivided electrode SCOML in aplan view. The second touch detection electrode STDL arranged at such aportion is located at a portion not in contact with the subdividedelectrode SCOML. The second touch detection electrode STDL arranged atsuch a portion forms capacitance with the subdivided electrode SCOML towhich the drive signal Vcom is output. In FIG. 15 and other figures, thecapacitance formed by combining the second touch detection electrodeSTDL and the subdivided electrode SCOML is schematically illustrated bya dashed line CA. In FIG. 15 and other figures, although only thecapacitance for two subdivided electrodes SCOML is exemplified, thecapacitance is similarly generated for the other subdivided electrodesSCOML.

The subdivided electrode SCOML and the second touch detection electrodeSTDL having the positional relation described above have a configurationfor performing touch detection based on the same principle as that ofthe drive electrode COML and the first touch detection electrode TDL.The arrangement pitch of the subdivided electrodes SCOML is finer thanthat of the drive electrodes COML. The arrangement pitch of the secondtouch detection electrodes STDL is finer than that of the first touchdetection electrodes TDL. Thus, touch detection can be performed withhigher resolution. That is, it is possible to output a detection resultin which contact and non-contact on the cover member 5 caused by minuteroughness such as a fingerprint are distinguished from each other (referto FIG. 9).

The arrangement of the first touch detection electrodes TDL and thesecond touch detection electrodes STDL is determined based on a relation(interference and the like) between a sensor function implemented by thefirst touch detection electrode TDL and the drive electrode COML and asensor function implemented by the second touch detection electrode STDLand the subdivided electrode SCOML. Specifically, as illustrated in FIG.14, for example, the first touch detection electrode TDL and the secondtouch detection electrode STDL are arranged at the respective portionsnot overlapping each other in a plan view. This configuration canprevent one of the first touch detection electrode TDL and the secondtouch detection electrode STDL from being arranged at a portioninterposed between the other one thereof and the drive electrode COML.Thus, the display device 1 with a touch detection function can favorablyexhibit both sensor functions. For example, by causing the spacingbetween the first touch detection electrode TDL and the second touchdetection electrode STDL to be larger than the spacing between thesecond touch detection electrodes STDL, a possibility of interferencebetween an electric field formed between the first touch detectionelectrode TDL and the drive electrode COML and an electric field formedbetween the second touch detection electrode STDL and the subdividedelectrode SCOML can be further reduced. Thus, the display device 1 witha touch detection function can favorably exhibit both sensor functions.The arrangement of the first touch detection electrode TDL and thesecond touch detection electrode STDL can be appropriately modifiedbased on other reasons.

FIG. 16 is a schematic diagram illustrating an example of transition ofthe drive electrode COML to which the drive signal Vcom is output in thefirst mode in the display device 1 with a touch detection function. Thedisplay device 1 with a touch detection function operates in the firstmode when performing touch detection using the first touch detectionelectrode TDL. A purpose of touch detection using the first touchdetection electrode TDL is to detect a position of a touch operation inthe detection region, such as a position of a finger of a person in thedetection region. In FIG. 16 and FIG. 17 described later, the driveelectrodes are denoted by reference numerals C₁, C₂, . . . , C_(n) todistinguish the drive electrodes COML from each other. The subdividedelectrodes SCOML are denoted by reference numerals S₁, S₂, . . . , S_(m)to distinguish the subdivided electrodes SCOML from each other.

In the first mode, the drive signal Vcom is output in units of the driveelectrode COML. Specifically, as illustrated in FIG. 16, for example,the drive signal Vcom is output to scan the drive electrodes C₁, C₂, . .. , C_(n) arranged in parallel with each other. During the scanning, thedrive signal Vcom is output to each of the drive electrodes COML insuccession at a predetermined cycle. Irrespective of whether the driveelectrode COML includes the subdivided electrode SCOML, the drive signalVcom is output in units of the drive electrode COML. That is, regardingone drive electrode COML2(C_(n)) including the subdivided electrodesSCOML, the drive signal Vcom is output to all of the subdividedelectrodes SCOML included in the one drive electrode COML2 at the sametime. The width of the region in which the subdivided electrodes SCOMLof one drive electrode COML2 are arranged in parallel with each other issubstantially equal to that of the drive electrode COML1 not includingthe subdivided electrode SCOML. Thus, by outputting the drive signalVcom to all of the subdivided electrodes SCOML included in one driveelectrode COML2 at the same time, a touch detection range based on thedetection block of the one drive electrode COML2 and a touch detectionrange based on the detection block in a case of outputting the drivesignal Vcom to one drive electrode COML1 not including the subdividedelectrode SCOML can be substantially equivalently handled.

FIG. 17 is a schematic diagram illustrating an example of transition ofthe subdivided electrode SCOML to which the drive signal Vcom is outputin the second mode in the display device 1 with a touch detectionfunction. The display device 1 with a touch detection function operatesin the second mode when performing touch detection using the secondtouch detection electrode STDL. A purpose of touch detection using thesecond touch detection electrode STDL is to detect a shape of adetection target that is hardly detected with the arrangement pitch ofthe first touch detection electrodes TDL, such as a fingerprint of afinger of a person, in a region in which the second touch detectionelectrode STDL is arranged.

In the second mode, the drive signal Vcom is output in units of thesubdivided electrode SCOML. Specifically, as illustrated in FIG. 17, forexample, the drive signal Vcom is output to scan the subdividedelectrodes S₁, S₂, . . . , S_(m) arranged in parallel with each other.During the scanning, the drive signal Vcom is output to each of thesubdivided electrodes SCOML in succession at a predetermined cycle. Inthe present embodiment, in the second mode in which the drive signalVcom is output in units of the subdivided electrode SCOML, the drivesignal Vcom is not output to the drive electrode COML1 not including thesubdivided electrode SCOML.

In this way, one drive electrode COML2 including the subdividedelectrodes SCOML is provided such that switching is enabled between thefirst mode in which drive signal Vcom is collectively output to thesubdivided electrodes SCOML of the one drive electrode COML2 and thesecond mode in which the drive signal Vcom is individually output toeach subdivided electrode SCOML.

The drive electrode driver 14 functions as a drive circuit that switchesbetween the first mode and the second mode to output the drive signalVcom to the drive electrode COML. The drive electrode driver 14according to the embodiment is configured to switch between the twomodes, that is, the mode (first mode) in which the drive electrodedriver 14 handles a plurality of subdivided electrodes SCOML as onedrive electrode COML to collectively output the drive signal Vcom to thesubdivided electrodes SCOML and the mode (second mode) in which thedrive electrode driver 14 individually outputs the drive signal Vcom toeach of the subdivided electrodes SCOML. Specifically, the driveelectrode driver 14 is configured to switch an output target of thedrive signal Vcom between units made up of a drive electrode and unitsmade up of a subdivided electrode SCOML, using a shift register method,for example. The drive electrode driver 14 is capable of changing avoltage of the drive signal Vcom to an appropriate voltage for each of acase in which the output target of the drive signal Vcom is units madeup of a drive electrode and a case in which the output target of thedrive signal Vcom is units made up of a subdivided electrode SCOML.

In FIG. 16, the drive signal Vcom is output to one drive electrode COMLat a time. However, the drive signal Vcom may be output to a pluralityof drive electrodes COML at the same time. In such a case, the driveelectrodes COML to which the drive signal Vcom is output make atransition at a predetermined cycle to perform scanning. The subdividedelectrodes SCOML to which the drive signal Vcom is output at the sametime in FIG. 17 are handled in the same manner as the drive electrodesCOML.

FIG. 18 is a timing chart illustrating an operation example of thedisplay device 1 with a touch detection function. In FIG. 18 and FIG. 19described later, Scan1 represents an output of the drive signal in thefirst mode. In FIG. 18 and FIG. 19, Scan2 represents an output of thedrive signal in the second mode. In the embodiment, a display outputperiod (period P₁) and a sensing period (period P₂) are alternatelyrepeated in a time division manner Specifically, as illustrated in FIG.18, for example, the display device 1 with a touch detection functiondisplays and outputs an image of one frame by a predetermined number oflines. In a period (frame period 1F) required to display the entireimage of one frame, the period P₁ in which the image corresponding tothe predetermined number of lines is displayed and the period P₂ inwhich sensing using any one of the first touch detection electrode TDLand the second touch detection electrode STDL is performed arealternately repeated.

More specifically, in accordance with an output timing (refer to theline SIGn) of the pixel signals Vpix corresponding to the predeterminednumber of lines in the period P₁, display output is performed with thepixels Pix corresponding to the lines (refer to the line SEL R/G/B). Theperiod P₂ is a period between output timings of pixel signals Vpixcorresponding to the predetermined number of lines. The line TS-VD inthe period P₂ represents a timing of vertical synchronization controlfor sensing, and the line TS-HD represents a timing of horizontalsynchronization control for sensing. In the embodiment, sensing startsin accordance with a rising timing of the line TS-VD, and the drivesignal Vcom for sensing is output in a rising period of the line TS-HD.

At an output timing of the drive signal Vcom in the period P₂, sensingis performed using the first touch detection electrode TDL or the secondtouch detection electrode STDL. In the example illustrated in FIG. 18,the display device 1 with a touch detection function performs touchdetection using the first touch detection electrode TDL, what is calledposition detection of a touch operation in the detection region, in theframe period 1F of the first frame (F₁). In the touch detection usingthe first touch detection electrode TDL, the drive signal Vcom is outputin units of the drive electrode COML. The display device 1 with a touchdetection function performs touch detection using the second touchdetection electrode STDL, such as fingerprint detection, in the frameperiod 1F of the second frame (F₂). In the touch detection using thesecond touch detection electrode STDL, the drive signal Vcom is outputin units of the subdivided electrode SCOML.

FIG. 19 is a timing chart illustrating another operation example of thedisplay device 1 with a touch detection function. In the exampledescribed with reference to FIG. 18, the period P₂ in which the firsttouch detection electrode TDL is used and the period P₂ in which thesecond touch detection electrode STDL is used have the same periodlength. However, the periods may have different period lengths. Forexample, one rising period (period P₄) of the line TS-HD in a case ofusing the second touch detection electrode STDL may be longer than onerising period (period P₃) of the line TS-HD in a case of using the firsttouch detection electrode TDL. Specifically, as illustrated in FIG. 19,for example, the period P₄ may be an integral multiple (for example, twotimes) of the period P₃. In this case, a relation between the period P₄and the period P₃ may correspond to a relation between the lengths ofthe periods (periods P₆ and P₅) for display output performed alternatelywith sensing. Specifically, as illustrated in FIG. 19, for example, aratio between the period P₄ and the period P₃ may be equal to a ratiobetween the period P₆ for display output in the frame period 1F (F₂)including the period P₄ and the period P₅ for display output in theframe period 1F (F₁) including the period P₃ (for example, 2:1).

The drive electrode driver 14, the first touch detection unit 40, andthe second touch detection unit 60 operate in a predetermined routine toperform processing related to display output and sensing. Specifically,the drive electrode driver 14, the first touch detection unit 40, andthe second touch detection unit 60 perform processing related to displayoutput and sensing by time division control described above withreference to FIG. 18 or FIG. 19, for example. A switching timing betweenthe period for display output and the period for sensing depends on theclock signal output from the control unit 11, for example.

The second touch detection unit 60 performs various pieces of processingrelated to fingerprint detection with the subdivided electrode SCOML andthe second touch detection electrode STDL. Specifically, for example,the synthesizing unit 67 combines the second touch detection signalsVdet2 from the second touch detection electrodes STDL to generatetwo-dimensional information indicating the shape of the externalproximity object performing a touch operation with the second touchdetection electrode STDL. In this way, based on variation in capacitanceat the second touch detection electrode STDL, the second touch detectionunit 60 outputs a detection result corresponding to roughness of theobject performing a touch operation.

A method of determining which one of the first touch detection electrodeTDL and the second touch detection electrode STDL is used for sensing isfreely predetermined. For example, it may be predetermined throughcontrol by the control unit 11. Specifically, for example, the controlunit 11 receives, from an external circuit, the control signal (thefingerprint-detection implementation signal Vtouch) indicatingimplementation of fingerprint detection. The control unit 11 causes thedrive electrode driver 14 to output the drive signal Vcom in units ofthe subdivided electrode SCOML in a period in which a flag of thefingerprint-detection implementation signal Vtouch is ON, and causes thedrive electrode driver 14 to output the drive signal Vcom in units ofthe drive electrode COML in a period in which the flag of thefingerprint-detection implementation signal Vtouch is OFF. With such amechanism, the electronic apparatus including the display device 1 witha touch detection function can perform fingerprint detection at adesired timing if application software and the like including controlfunctions related to ON/OFF of the output of the fingerprint-detectionimplementation signal Vtouch are installed thereon, for example. Theelectronic apparatus can perform switching, at a desired timing, betweenposition detection of the touch operation in the detection region andfingerprint detection.

The display device 1 with a touch detection function may perform displayoutput for prompting fingerprint detection in the frame period 1Fincluding the sensing period in which touch detection is performed usingthe second touch detection electrode STDL. Specifically, for example, ina period in which the application software described above causes thefingerprint-detection implementation signal Vtouch to be ON, the displaydevice 1 with a touch detection function can perform such display outputby outputting the video signal Vdisp for displaying an image suggestingthat the region in which the second touch detection electrode STDL isarranged is touched by a finger.

In the description with reference to FIG. 18 and FIG. 19, switchingbetween sensing using the first touch detection electrode TDL andsensing using the second touch detection electrode STDL is performed ona frame-period-by-frame-period basis. However, the timing of switchingis not limited thereto and can be appropriately modified. For example,the period of sensing using the first touch detection electrode TDL andthe period of sensing using the second touch detection electrode STDLmay be included in the same frame period 1F.

As described above, according to the embodiment, one drive electrodeCOML2 including a plurality of subdivided electrodes SCOML is providedsuch that switching is enabled between the first mode in which the drivesignal Vcom is collectively output to the subdivided electrodes SCOML ofthe one drive electrode COML2 and the second mode in which the drivesignal Vcom is individually output to each of the subdivided electrodesSCOML. Due to this, touch detection corresponding to an arrangementpitch of a target to which the drive signal Vcom is output can beselectively used in the first mode and the second mode. For example, thedrive electrode COML2 including the subdivided electrode SCOML can beused in both of the first mode for mainly performing position detectionof a touch operation in the detection region and the second mode formainly performing detection with higher resolution than that of theposition detection (for example, detection of the shape (pattern) of thefingerprint). Thus, a dedicated drive electrode used only for the secondmode is not required. Accordingly, the detection region with higherresolution used for detecting the fingerprint and the like can also beused as the detection region of the touch operation. The positiondetection and the detection with higher resolution than that of theposition detection can be performed with a smaller number of components.

The display device 1 with a touch detection function includes the secondtouch detection electrode STDL arranged in a partial region of thedetection region. The second touch detection electrode STDL is arrangedat a portion not in contact with the subdivided electrode SCOML andwhere the second touch detection electrode STDL forms capacitance withthe subdivided electrode SCOML to which the drive signal Vcom is output.Due to this, the detection region with higher resolution used fordetecting the fingerprint and the like can also be used as the detectionregion of the touch operation.

The display device 1 with a touch detection function includes aplurality of second touch detection electrodes STDL. Due to this,detection can be performed with higher accuracy using the second touchdetection electrodes STDL.

The second touch detection electrodes STDL are arranged at a pitch finerthan the arrangement pitch of the first touch detection electrodes TDL.Due to this, resolution of detection using the second touch detectionelectrodes STDL can be caused to be higher than resolution of detectionusing the first touch detection electrode TDL.

The second touch detection electrode STDL is arranged closer to thecover member than the first touch detection electrode TDL is. Due tothis, sensitivity of touch detection with the second touch detectionelectrode can be easily enhanced.

Modification

The arrangement of each component in the embodiment of the presentinvention can be appropriately modified. The following describesmodifications of the embodiment with reference to FIGS. 20 to 31.

First Modification

FIG. 20 is a cross-sectional view illustrating a positional relationbetween the drive electrodes COML1 and COML2, the subdivided electrodeSCOML, the first touch detection electrode TDL, the second touchdetection electrode STDL, and the like according to a first modificationof the embodiment. In FIG. 15, the cover member 5 has the first surfacefacing the counter substrate 3 and the second surface opposite to thefirst surface. The touch operation is performed with the second surface.The second touch detection electrode STDL is arranged on the firstsurface of the cover member 5. Alternatively, the second touch detectionelectrode STDL may be arranged at another portion. For example, asillustrated in FIG. 20, the second touch detection electrode STDL may bearranged in the same layer as the first touch detection electrode TDL.The first touch detection electrode TDL and the second touch detectionelectrode STDL can be collectively formed through one process when theyare to be arranged in the same layer.

Second Modification

FIG. 21 is a cross-sectional view illustrating a positional relationbetween the drive electrodes COML1 and COML2, the subdivided electrodeSCOML, the first touch detection electrode TDL, the second touchdetection electrode STDL, and the like according to a secondmodification of the embodiment. As illustrated in FIG. 21, the secondtouch detection electrode STDL may be arranged on the second surface ofthe cover member 5, the second surface is a surface with which the touchoperation is performed by a finger and the like. Due to this,sensitivity of detection can be easily enhanced.

Third Modification

FIG. 22 is a cross-sectional view illustrating a positional relationbetween the drive electrodes COML1 and COML2, the subdivided electrodeSCOML, the first touch detection electrode TDL, the second touchdetection electrode STDL, and the like according to a third modificationof the embodiment. As illustrated in FIG. 22, the first surface of thecover member may have a stepped part 5 a, the stepped part 5 a beingdented toward the second surface with which the touch operation isperformed. The second touch detection electrode STDL is arranged on abottom face of the stepped part 5 a. In this way, the second touchdetection electrode STDL may be located at a portion embedded in thecover member 5.

In the same manner as the embodiment, the second touch detectionelectrode STDL formed through the same process as that of printing ofwiring on the substrate may be arranged on the stepped part 5 a, or afilm on which wiring that serves as the second touch detection electrodeSTDL is formed may be attached to the stepped part 5 a.

Fourth Modification

FIG. 23 is a plan view schematically illustrating a display device 1Awith a touch detection function according to a fourth modification ofthe embodiment. A positional relation between the drive electrode COML(and the subdivided electrode SCOML), the first touch detectionelectrode TDL (and the second touch detection electrode STDL), and thelike in a plan view is not limited to the positional relation accordingto the embodiment, and can be appropriately modified. In the aboveembodiment, the first touch detection electrode TDL extends along thelong side of the rectangular display region, and the drive electrodeCOML extends along the short side. Alternatively, as illustrated in FIG.23, the long and short sides and the positional relation between thedrive electrode COML and the first touch detection electrode TDL may bereversely combined. That is, in the display device 1A with a touchdetection function, the drive electrode COML may extend along the longside of a rectangular region (for example, the display region) includingthe detection region, and the first touch detection electrode TDL mayextend along the short side.

FIG. 24 is a C-C cross-sectional view illustrating a positional relationbetween the drive electrode COML, the subdivided electrode SCOML, thefirst touch detection electrode TDL, the second touch detectionelectrode STDL, and the like according to the fourth modification of theembodiment. The drive electrode COML2 including the subdivided electrodeSCOML according to the fourth modification is arranged, for example, inthe vicinity of the center in a direction along the short side of therectangular display region. Accordingly, as illustrated in FIG. 24, thedrive electrode COML2 including the subdivided electrode SCOML isarranged between the drive electrodes COML1.

FIG. 25 is a diagram illustrating an example of a configuration arrangedon the cover member 5 according to the fourth modification. FIG. 26 is aplan view illustrating an example of a positional relation between thefirst touch detection electrode TDL and the second touch detectionelectrode STDL according to the fourth modification. The second touchdetection electrode STDL according to the fourth modification isarranged on the cover member 5 as illustrated in FIG. 25, for example.As illustrated in FIG. 26, the first touch detection electrode TDL onthe counter substrate 3 and the second touch detection electrode STDL onthe cover member 5 extend in the same direction (for example, adirection along the short side).

In FIG. 25, the second touch detection electrode STDL has a lengthacross the entire short side of the display region. However, the lengthof the second touch detection electrode STDL can be appropriatelymodified. In the same manner as above embodiment, it is only requiredthat the second touch detection electrode STDL is arranged in a partialregion of the detection region, and at a portion not in contact with thesubdivided electrode SCOML and where the second touch detectionelectrode STDL forms capacitance with the subdivided electrode SCOML towhich the drive signal Vcom is output.

In the above embodiment, the second touch detection unit 60 is arrangedon the FPC 70 extending toward the outside of the substrate, but this ismerely an arrangement example of the second touch detection unit 60. Theembodiment is not limited thereto, and can be appropriately modified.For example, as illustrated in FIG. 25, the second touch detection unit60 may be arranged on the cover member 5. Specifically, for example, thesecond touch detection unit 60 may be arranged on the first surface ofthe cover member 5, which faces the counter substrate 3, in the samemanner as the second touch detection electrode STDL illustrated in FIG.24.

FIG. 27 is a diagram illustrating another example of arrangement of thesecond touch detection unit 60 according to the fourth modification. Asillustrated in FIG. 27, the second touch detection unit 60 may bearranged on a wiring substrate such as an FPC (for example, the FPC 72)extending from the first surface of the cover member 5, which faces thecounter substrate 3. According to the examples illustrated in FIGS. 25and 27, in this case, formation of wiring that couples the second touchdetection electrode STDL to the second touch detection unit 60 can becompleted on the counter substrate 3 side of the cover member 5.

Although FIGS. 25 and 27 do not illustrate the wiring between the secondtouch detection electrode STDL and the second touch detection unit 60,actually, the wiring such as metal wiring is formed in the picture frameregion 101 b, and the wiring couples the second touch detectionelectrode STDL to the second touch detection unit 60.

FIG. 28 is a block diagram illustrating a configuration example of thedisplay device 1A with a touch detection function according to thefourth modification. In the above embodiment, the single drive electrodedriver 14 outputs the drive signal Vcom to each individual driveelectrode COML and to each individual subdivided electrode SCOML.Alternatively, a configuration of outputting the drive signal Vcom toeach individual drive electrode COML in the first mode may be separatedfrom a configuration of outputting the drive signal Vcom to eachindividual subdivided electrode SCOML in the second mode. Specifically,as illustrated in FIGS. 23 and 28, for example, the drive electrodedriver 14 that outputs the drive signal Vcom to each individual driveelectrode COML and a subdivided electrode driver 90 that outputs thedrive signal Vcom to each individual subdivided electrode SCOML may beseparately provided. In this case, the subdivided electrode driver 90 iscoupled to each the subdivided electrodes SCOML of the drive electrodeCOML2, so that the subdivided electrode driver 90 individually outputsthe drive signal Vcom to each of the subdivided electrodes SCOML. Thesubdivided electrode driver 90 is, for example, what is called ascanning circuit, and successively switches the subdivided electrodeSCOML to which the drive signal Vcom is output in response to the clocksignal.

The drive electrode driver 14 and the subdivided electrode driver 90that are separately provided as illustrated in the examples of FIGS. 23and 28 determine a state of an output of the drive signal Vcom for touchdetection under control of the control unit 11, for example.Specifically, in the first mode, the control unit 11 causes the driveelectrode driver 14 to output the drive signal Vcom to each individualdrive electrode COML. In the second mode, the control unit 11 causes thesubdivided electrode driver 90 to output the drive signal Vcom to eachindividual subdivided electrode SCOML.

Fifth Modification

FIG. 29 is a plan view illustrating a positional relation between thedrive electrodes COML1 and COML2, the subdivided electrode SCOML, andthe second touch detection electrode STDL according to a fifthmodification. Although a plurality of second touch detection electrodesSTDL are provided in the above embodiment (refer to FIG. 14) and thefourth modification (refer to FIGS. 24 and 25), the number of the secondtouch detection electrodes STDL may be one as illustrated in FIG. 29,for example. If the number of the second touch detection electrodes STDLis one, the second touch detection unit 60 can detect a fingerprint whena finger moves along a direction in which the subdivided electrode SCOMLis extended while performing a touch operation on the second touchdetection electrode STDL, for example. That is, assuming that a part ofthe fingerprint detected by the second touch detection electrode STDLvaries in accordance with movement of the finger, touch detection isperformed multiple times in the second mode using one second touchdetection electrode STDL while the finger is moving. Due to this, adetection result corresponding to a plurality of lines detected by aplurality of second touch detection electrodes STDL as illustrated inFIG. 9 can be obtained with one touch detection electrode. The secondtouch detection electrode STDL according to the fifth modificationoutputs the second touch detection signal Vdet2 via wiring SL, forexample.

Sixth Modification

FIG. 30 is a plan view illustrating a positional relation between thedrive electrodes COML1 and COML2, the subdivided electrode SCOML, andthe second touch detection electrode STDL according to a sixthmodification. In FIG. 29, the number of the second touch detectionelectrodes STDL is one. Alternatively, assuming that the finger moves, aplurality of second touch detection electrodes (for example, two secondtouch detection electrodes STDL1 and STDL2) may be provided. The secondtouch detection electrode STDL1 according to the sixth modificationoutputs the second touch detection signal Vdet2 via wiring SL1, forexample. The second touch detection electrode STDL2 outputs the secondtouch detection signal Vdet2 via wiring SL2, for example.

When the two second touch detection electrodes STDL1 and STDL2 areprovided as illustrated in FIG. 30, assuming that the part of thefingerprint detected by the second touch detection electrodes STDL1 andSTDL2 varies in accordance with movement of the finger, touch detectionis performed multiple times in the second mode using the two secondtouch detection electrodes STDL1 and STDL2 while the finger is moving.Because the finger moves, a detection result obtained by the secondtouch detection electrode STDL1 at a first timing is substantially thesame as that obtained by the second touch detection electrode STDL2 at asecond timing. The difference between the first timing and the secondtiming depends on the moving speed of the finger. That is, as the movingspeed of the finger with respect to the two second touch detectionelectrodes STDL1 and STDL2 increases, the difference between the firsttiming and the second timing is reduced. Thus, on the precondition thatthe finger moves, a plurality of second touch detection electrodes STDLallow obtaining the moving speed of the finger in touch detection forfingerprint detection. Based on such a moving speed of the finger,parameters related to various data corrections can be set under morefavorable condition, the parameters including a degree of overlappingbetween detection results related to acquirement of the fingerprint bysynthesizing detection results and the like. Thus, according to thesixth modification, accuracy in synthesizing the detection results canbe further improved.

The drive electrodes COML in FIG. 29 include two drive electrodes COML2arranged in parallel with each other, and the drive electrodes COML inFIG. 30 include one drive electrode COML2. However, this is merely anexample of variation of arrangement of the drive electrode COML2including the subdivided electrode SCOML. The arrangement is not limitedthereto, and can be appropriately modified. In the above embodiment andmodifications, the number and the arrangement of the drive electrodesCOML2 including the subdivided electrodes SCOML are freely determined.The extending length and the arrangement of the second touch detectionelectrode STDL are preferably determined in accordance with the numberand the arrangement of the drive electrodes COML2 including thesubdivided electrodes SCOML.

When a plurality of drive electrodes COML2 are arranged in parallel witheach other as illustrated in FIG. 29, the touch detection using thefirst touch detection electrode TDL in the first mode may be performedprior to the second mode so as to detect the position of the finger inthe detection region. In this case, the drive signal Vcom is output, inthe second mode, to the subdivided electrodes SCOML included in thedrive electrode COML2 corresponding to the position of the fingerobtained based on the detection result in the first mode. Thus, thenumber of the subdivided electrodes SCOML can be further reduced, thesubdivided electrodes SCOML to which the drive signal Vcom is output intouch detection using the second touch detection electrode STDL, such asfingerprint detection. Accordingly, power consumption can be reduced.Time required for touch detection with the same accuracy can also bereduced as compared with a case in which the drive signal Vcom is outputto all of the subdivided electrodes SCOML. Considering a case in whichtouch detection is performed using the second touch detection electrodeSTDL within the same time, the time required for outputting the drivesignal Vcom to all of the subdivided electrodes SCOML can be assigned tothe time for outputting the drive signal Vcom multiple times to asmaller number of subdivided electrodes SCOML, so that touch detectioncan be performed multiple times. In this case, accuracy in detection canbe easily enhanced.

Seventh Modification

FIG. 31 is an explanatory diagram for explaining an example of anoperation of code-division multiplexed driving. In the above embodimentwith reference to FIG. 9, exemplified is a case in which the secondtouch detection electrode STDL individually performs detection.Alternatively, a plurality of second touch detection electrodes STDL maybe utilized at the same time to perform touch detection. Specifically,as illustrated in FIG. 31, for example, in the display device 1 with atouch detection function, the drive electrode driver 14 (or thesubdivided electrode driver 90) selects a plurality of (four, in theexample of FIG. 31) subdivided electrode blocks Tx1, Tx2, Tx3, and Tx4of a selected subdivided electrode blocks Bkn at the same time andsupplies, to the selected subdivided electrode blocks Bkn, the drivesignal Vcom the phase of which is determined based on a predeterminedcode. In FIG. 31, waveforms illustrated on the right side of thesubdivided electrode blocks Tx1, Tx2, Tx3, and Tx4 each exemplify thephase of the drive signal Vcom. For example, the predetermined code isdefined with a square matrix represented by the following expression(1). An order of the square matrix of the expression (1) is four, whichis the number of the subdivided electrode blocks Tx1, Tx2, Tx3, and Tx4of the selected subdivided electrode blocks Bkn. A diagonal component“−1” in the square matrix of the expression (1) is different from acomponent “1” other than the diagonal component in the square matrix.The code “−1” is a code for supplying the drive signal Vcom the phase ofwhich is determined to be different from that of the code “1”. The driveelectrode driver 14 and the like apply the drive signal Vcom based onthe square matrix in the expression (1) so that the phase of theabove-described AC rectangular wave Sg corresponding to the component“1” other than the diagonal component in the square matrix and the phaseof the above-described AC rectangular wave Sg corresponding to thediagonal component “−1” in the square matrix are reversed.

$\begin{matrix}{{\begin{pmatrix}{- 1} & 1 & 1 & 1 \\1 & {- 1} & 1 & 1 \\1 & 1 & {- 1} & 1 \\1 & 1 & 1 & {- 1}\end{pmatrix}\begin{pmatrix}1.8 \\2.2 \\1.8 \\1.8\end{pmatrix}} = \begin{pmatrix}4.0 \\3.2 \\4.0 \\4.0\end{pmatrix}} & (1)\end{matrix}$

When a plurality of second touch detection electrodes STDL are utilizedat the same time like the selected subdivided electrode blocks Bkndescribed above, the second touch detection unit 60 performs detectionusing a code division multiplex (CDM) system.

For example, when an external proximity object CQ such as a finger ispresent at the subdivided electrode block Tx2, which is the secondposition from an upstream side of scanning in the subdivided electrodeblocks Tx1, Tx2, Tx3, and Tx4 of the selected subdivided electrodeblocks Bkn, a difference voltage is caused by the external proximityobject CQ by mutual induction (for example, the difference voltage isassumed to be 20%). In such an example, the second touch detectionsignal Vdet2 (sensor output signal) detected by the second touchdetection unit 60 in a first detection (first time zone) is representedas (−1)+(0.8)+(1)+(1)=1.8. In the expression, “1.8” is signal intensitywith reference to the signal intensity of the drive signal Vcom of thecode “1”. The second touch detection signal Vdet2 detected by the secondtouch detection unit 60 in a second detection (second time zone)subsequent to the first time zone is represented as(1)+(−0.8)+(1)+(1)=2.2. The second touch detection signal Vdet2 detectedby the second touch detection unit 60 in a third detection (third timezone) subsequent to the second time zone is represented as(1)+(0.8)+(−1)+(1)=1.8. The second touch detection signal Vdet2 detectedby the second touch detection unit 60 in a fourth detection (fourth timezone) subsequent to the third time zone is represented as(1)+(0.8)+(1)+(−1)=1.8.

The coordinate extracting unit 65 multiplies the second touch detectionsignals Vdet2 (sensor output signals) detected by the signal processingunit 64 using the square matrix of the expression (1). The coordinateextracting unit 65 detects that there is the external proximity objectCQ such as a finger at the position of the subdivided electrode blockTx2 of the selected subdivided electrode blocks Bkn with detectionsensitivity having higher accuracy (for example, four times) than thatof time division multiplex (TDM) driving without increasing the voltageof the signal output as the drive signal Vcom.

According to the seventh modification, sensitivity of touch detection inthe second mode is further enhanced. Thus, according to the seventhmodification, touch detection accuracy can be improved. According to theseventh modification, the touch detection in the second mode can becompleted in a short time. In particular, the arrangement pitch of thesubdivided electrodes SCOML is finer than that of the drive electrodesCOML, so that a degree of variation in voltage based on capacitancegenerated in accordance with the drive signal Vcom to one subdividedelectrode SCOML, that is, a degree of variation in capacitancecorresponding to presence/absence of a touch operation tends to besmaller. The arrangement pitch of the second touch detection electrodesSTDL is finer than that of the first touch detection electrodes TDL, sothat such a degree of variation tends to be smaller. In the second mode,the arrangement pitch of the electrodes for touch detection is finerthan that in the first mode, so that difficulty in securing highsensitivity of touch detection is increased. Under such a condition, byusing the CDM system in the second mode, sufficient sensitivity can beeasily secured.

In the description with reference to FIG. 31 and the expression (1), thenumber of the subdivided electrode blocks (Tx1, Tx2, Tx3, and Tx4)included in the selected subdivided electrode blocks Bkn is four.However, this is merely an example to clarify the description, and thenumber is not limited thereto. The number of the subdivided electrodeblocks included in the selected subdivided electrode blocks Bkn can beappropriately modified (for example, 128).

The characteristics of configurations described in the embodiment andmodifications can be applied to each other only in a range in which theydo not contradict each other. For example, the arrangement of the secondtouch detection unit 60 in the embodiment may be the same as that in thefourth modification, or the arrangement of the second touch detectionunit 60 in the fourth modification may be the same as that in theembodiment. The extending direction of the drive electrodes COML can beany direction in the configurations in the fifth and the sixthmodifications, so that the configuration of the fifth and the sixthmodification can be applied to the embodiment and the fourthmodification. The position of the second touch detection electrode inthe fourth modification may be that in the first to the thirdmodifications. The seventh modification can be combined with any of theembodiment and the other modifications.

The preferred embodiment of the present invention and the modificationsthereof (embodiment and the like) have been described above. However,the present invention is not limited thereto. Content disclosed in theembodiment and the like is merely an example, and various modificationscan be made without departing from the gist of the invention. Thepresent invention naturally encompasses an appropriate modificationmaintaining the gist of the invention.

For example, in the embodiment and the like, described is a case inwhich the drive electrode COML also functions as the common electrode ofthe display panel 20. However, the embodiment is not limited thereto.The display device with a touch detection function may be configuredsuch that the common electrode is arranged on the display panel and suchthat the touch panel is mounted on the display panel.

In the above embodiment and the like, the first detection unit (firsttouch detection unit 40) and the second detection unit (second touchdetection unit 60) are separately provided. Alternatively, one circuitmay have functions of such two circuits.

In the above embodiment and the like, the first touch detectionelectrode TDL and the second touch detection electrode STDL areseparately arranged. Alternatively, the arrangement pitch of the firsttouch detection electrodes TDL may be the same as that of the secondtouch detection electrodes STDL, and the first touch detectionelectrodes TDL and the second touch detection electrodes STDL may be thesame electrodes. Also in this case, with the configuration including thedrive electrode COML2 including the subdivided drive electrode SCOML,resolution of detection in the first mode is different from that of thesecond mode, so that an operation corresponding to a purpose can beperformed such as a distinguishing operation between identifying theposition of the finger and detecting a fingerprint.

Numerical values such as the number of the drive electrodes COML, thenumber of the subdivided electrodes included in one drive electrodeCOML2, the number of the first touch detection electrodes TDL, and thenumber of the second touch detection electrodes STLD exemplified in theembodiment and illustrated in the drawings are merely an example, andcan be appropriately modified.

What is claimed is:
 1. A touch detection device that detects a touchoperation in a detection region based on variation in capacitance, thetouch detection device comprising: a plurality of drive electrodesarranged in parallel with each other in the detection region; and aplurality of first touch detection electrodes arranged in parallel witheach other in the detection region, each of the first touch detectionelectrodes being arranged at a portion not in contact with the driveelectrodes and where the first touch detection electrode formscapacitance with a drive electrode to which a drive signal is output,wherein the drive electrodes includes a drive electrode including aplurality of subdivided electrodes an arrangement pitch of which isfiner than an arrangement pitch of the drive electrodes, and the driveelectrode including the subdivided electrodes is provided such thatswitching is enabled between a first mode in which the drive signal iscollectively output to the subdivided electrodes of the drive electrodeand a second mode in which the drive signal is individually output toeach of the subdivided electrodes of the drive electrode.
 2. The touchdetection device according to claim 1, further comprising a second touchdetection electrode arranged in a partial region of the detectionregion, and arranged at a portion not in contact with the subdividedelectrodes and where the second touch detection forms capacitance with asubdivided electrode to which the drive signal is output.
 3. The touchdetection device according to claim 2, wherein the drive electrodes andthe first touch detection electrodes are arranged on a side of a firstsurface of a cover member arranged in the detection region, the firstsurface of the cover member being opposite to a second surface of thecover member with which the touch operation is performed, and the secondtouch detection electrode is closer to the cover member than the firsttouch detection electrodes are.
 4. The touch detection device accordingto claim 3, wherein the second touch detection electrode is arranged ata portion embedded in the cover member.
 5. The touch detection deviceaccording to claim 2, wherein the drive electrodes and the first touchdetection electrodes are arranged on a side of a first surface of acover member arranged in the detection region to form a multilayerstructure, the first surface of the cover member being opposite to asecond surface of the cover member with which the touch operation isperformed, the second touch detection electrode is arranged in the samelayer as the first touch detection electrodes.
 6. The touch detectiondevice according to claim 2, further comprising: a first detection unitthat detects a touch operation based on variation in capacitance at thefirst touch detection electrodes; and a second detection unit thatoutputs a detection result corresponding to roughness of an objectperforming a touch operation based on variation in capacitance at thesecond touch detection electrode.
 7. The touch detection deviceaccording to claim 6, wherein the second detection unit performsdetection using a code division multiplex system.
 8. The touch detectiondevice according to claim 2, wherein, the touch detection devicecomprises a plurality of the second touch detection electrodes arrangedin the partial region of the detection region, and an arrangement pitchof the second touch detection electrodes is finer than an arrangementpitch of the first touch detection electrodes.
 9. A display device witha touch detection function that detects a touch operation in a detectionregion on a display surface side of the display device based onvariation in capacitance, the display device with a touch detectionfunction comprising: a plurality of drive electrodes arranged inparallel with each other in the detection region; and a plurality offirst touch detection electrodes arranged in parallel with each other inthe detection region, each of the first touch detection electrodes beingarranged at a portion not in contact with the drive electrodes and wherethe first touch detection electrode forms capacitance with a driveelectrode to which a drive signal is output, wherein the driveelectrodes includes a drive electrode including a plurality ofsubdivided electrodes an arrangement pitch of which is finer than anarrangement pitch of the drive electrodes, and the drive electrodeincluding the subdivided electrodes is provided such that switching isenabled between a first mode in which the drive signal is collectivelyoutput to the subdivided electrodes of the drive electrode and a secondmode in which the drive signal is individually output to each of thesubdivided electrodes of the drive electrode.